$100 Challenge in Barcelona in 24 Hours

We arrived in Barcelona from Morocco and spent 24 hours exploring the city on a $100 budget, staying in an inexpensive Airbnb and using public transportation. We visited Las Ramblas, the Gothic Quarter, La Sagrada Família, the Magic Fountain, Park Güell, and the beach, while enjoying tapas, sangria, and seafood paella. We finished the challenge having spent $99.53.